Purpose:
Evidence from our laboratory demonstrates that hydrogen sulfide (H2S) (using sodium hydrosulfide, NaHS as a generator of H2S in biological tissues) can produce pharmacological effects in mammalian ocular tissues such as a decrease in intraocular pressure (IOP) in normotensive rabbits. In the present study we tested the hypothesis that the observed IOP-lowering effect of NaHS is mediated by an increase in aqueous humor outflow in porcine trabecular meshwork.

Methods:
Porcine ocular anterior segments explants containing only the trabecular meshwork were mounted on a perfusion chamber and perfused with Dulbecco’s Modified Eagle’s Medium (DMEM) at constant pressure of 7.35 mmHg and maintained at 37°C, 5% CO2. Once aqueous humor outflow was stable (~ 3 hours), ocular anterior segment explants were administered with different concentrations of NaHS (0.1 nM - 10 µM), and outflow was monitored for an additional 4 hours. Vehicle (0.1% saline) was run in parallel.